Triage step from the plan at C:\Users\erikn\.claude\plans\
i-did-some-work-sharded-acorn.md. Four sessions on issue #98 left the
worktree dirty with ~1352 LOC of mixed work. This commit splits the
work into "keep" (defensible + diagnostic) and "drop" (failed
experiments), then commits the keep set with the drops removed.
Plan asked for three commits (diag / fix / revert); consolidated to one
because the diagnostic emits in TransitionTypes.cs are tightly
interleaved with the multi-sphere CellTransit calls and the CellId
switch. Hunk-level splitting in those files for marginal bisect
granularity didn't justify the misclick risk.
Reverted entirely (failed experiments per slice 7 handoff):
- src/AcDream.Core/Physics/PhysicsDataCache.cs — neg-poly storage
fields (Stippling, PosSurface, NegSurface, HasNegativeSide,
IsNegativeSide, NegativeSide).
- src/AcDream.Core/Physics/ShadowObjectRegistry.cs — isBuilding flag
propagation through Register / ShadowEntry.
- tests/AcDream.Core.Tests/Physics/BSPQueryTests.cs — 165 lines of
PolygonWithNegativeSide_* tests.
- tests/AcDream.Core.Tests/Physics/ShadowObjectRegistryTests.cs —
isBuilding propagation tests.
- src/AcDream.Core/World/WorldEntity.cs — IsLandblockBuilding field
(no consumer once ShadowObjectRegistry.isBuilding is gone).
- src/AcDream.Core/World/LandblockLoader.cs — IsLandblockBuilding=true
setter on building entities (kept BuildBuildingTerrainCells).
- src/AcDream.App/Rendering/GameWindow.cs — isBuilding: arg passed to
ShadowObjects.Register.
- src/AcDream.Core/Physics/BSPQuery.cs — TryAdjustWalkableSide /
IsWalkableAt helpers, their callers, the Path 5 / Path 6 neg-poly
branch split, the BldgCheck-tied clearCell conditional, and the
neg-poly ResolveCellPolygons writes.
- src/AcDream.Core/Physics/PhysicsDiagnostics.cs — neg-poly fields
in the poly-dump format.
- src/AcDream.Core/Physics/TransitionTypes.cs — SpherePath.BldgCheck +
SpherePath.HitsInteriorCell fields and every consumer, the
savedBldgCheck try/finally around FindCollisions, and the neg-poly
format additions to the dump-on-error helper.
- src/AcDream.Core/Physics/CellTransit.cs — FindCellSet overloads
with hitsInteriorCell out-param and the BuildCellSetAndPickContaining
out-param threading.
Kept (defensible correctness fixes + diagnostic infrastructure):
- src/AcDream.App/Rendering/GameWindow.cs — render-vs-physics cell
origin split: the 0.02m render lift no longer leaks into physics
BSP caching. lb.BuildingTerrainCells threaded into LandblockMesh.Build.
- src/AcDream.Core/World/LoadedLandblock.cs — BuildingTerrainCells
record field.
- src/AcDream.Core/World/LandblockLoader.cs — BuildBuildingTerrainCells
(cy*8+cx from LandBlockInfo.Buildings).
- src/AcDream.Core/Terrain/LandblockMesh.cs — hiddenTerrainCells
param that collapses owned-cell triangles to a zero-area degenerate.
- src/AcDream.App/Streaming/{GpuWorldState,LandblockStreamer}.cs —
mechanical BuildingTerrainCells threading through LoadedLandblock
reconstructions.
- src/AcDream.Core/Physics/CellTransit.cs — multi-sphere
FindTransitCellsSphere variant + multi-sphere AddAllOutsideCells +
FindCellSet(IReadOnlyList<Sphere>, …) overload + the
BSPQuery.SphereIntersectsCellBsp call for loaded neighbours. Matches
retail CObjCell::find_cell_list / CEnvCell::find_transit_cells.
- src/AcDream.Core/Physics/TransitionTypes.cs — multi-sphere FindCellSet
call site, retail-faithful CellId switch after CheckOtherCells, the
outdoor-landcell terrain-walkable fallback in CheckOtherCells, and
the full diagnostic suite ([step-walk], [walkable-nearest],
[issue98-walkable-detail], [cell-set-summary], LastBspHitPoly
emits).
- src/AcDream.Core/Physics/PhysicsDiagnostics.cs — ProbeStepWalkEnabled
gate (ACDREAM_PROBE_STEP_WALK=1) + LogStepWalk helper + FormatVector
/ FormatPlane utilities. All emit-gated.
- src/AcDream.Core/Physics/BSPQuery.cs — diagnostic emits to
LastBspHitPoly at four sites in SphereIntersectsPolyInternal /
the placement adjustment path.
- Test files for the kept work: CellTransitFindCellSetTests,
CellTransitFindTransitCellsSphereTests, PhysicsDiagnosticsTests,
TransitionCheckOtherCellsTests, LandblockMeshTests,
LandblockLoaderTests.
Verification:
- dotnet build: green, 0 errors, 3 pre-existing warnings.
- dotnet test: 1156 passed + 8 failed (baseline was 1148 + 8 pre-
existing; the +8 passing are the new tests for the kept defensible
work). Same 8 pre-existing failures, no new regressions.
Backup of pre-triage worktree state in stash@{0}.
A6.P3 #98 is still open; this is the apparatus-prep step, not a fix.
Next: cell-dump probe (Step 2 of the plan).
Refactors FindCellList to delegate to a private helper
(BuildCellSetAndPickContaining) that returns BOTH the containing cell
id AND the full candidate HashSet. Public surface gains a new
FindCellSet overload; existing FindCellList behavior is unchanged.
Used by the upcoming Transition.CheckOtherCells (Phase A4) to iterate
every cell the sphere overlaps for per-cell BSP collision. Mirrors
retail's CObjCell::find_cell_list filling both cell_array AND var_4c
at acclient_2013_pseudo_c.txt:272725.
Three new unit tests cover sphere-fully-inside-primary,
sphere-straddling-portal, and outdoor-seed-neighbour-landcells cases.
Spec: docs/superpowers/specs/2026-05-20-phase-a4-multi-cell-bsp-design.md
Plan: docs/superpowers/plans/2026-05-20-phase-a4-multi-cell-bsp.md
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Erik